<?php
/**
 * Created by PhpStorm.
 * User: 氓羽
 * Date: 2018-3-31
 * Time: 11:39
 */
namespace Computer\Session;
class Computer{
    const YES = true;
    const NO = false;
    const ONE = 1;

    const  TWO = self::ONE+1;
    const THREE = self::TWO +1;
}

var_dump(Computer::THREE);